Current standards and recommendations for the laser beam welding are based on idea that identically polished edge surfaces without variations in the roughness and without any gap between the plates is the best setup in
butt joint welding.
For the three joint configurations, the results showed that face to edge
butt joints and edge to edge
butt joints were not significantly different at the 0.05 level.
Steel inserts without preheating were also used for creating
butt joints; however, the bond broke upon ejection from the mold.
In general, if a defect in the 5th lamination of group B occurred near an adjacent
butt joint in the 4th lamination, there could be a tendency of failure initiation from the joint, which continues through the defect.
Consider a
butt joint in a stressed glulam beam as a narrow gap or slot (Fig.
A
butt joint backer is basically a 4-ft.-long, 5- or 6-in.-wide board with 1/16-in.
Feathering out a
butt joint or skim-coating a whole wall is difficult because your knife leaves ridges on the broad surface--and touching them up often creates even more ridges.
The secret of making a
butt joint invisible is to keep your tape coat as thin as possible.
To make a
butt joint (Photo 2), open up the fold slightly and slide the top end over the lower piece, lapping about 2 in.